ALARM(S) UNIX System V ALARM(S)
Name
alarm - set a process alarm clock
Syntax
unsigned alarm (sec)
unsigned sec;
Description
The alarm system call instructs the alarm clock of the
calling process to send the signal SIGALRM to the calling
process after the number of real time seconds specified by
sec have elapsed [see signal(S)].
Alarm requests are not stacked; successive calls reset the
alarm clock of the calling process.
If sec is 0, any previously made alarm request is canceled.
The fork(S) system call sets the alarm clock of a new
process to 0. A process created by the exec(S) family of
calls inherits the time left on the old process's alarm
clock.
See Also
exec(S), fork(S), pause(S), signal(S), sigset(S).
Diagnostics
The alarm system call returns the amount of time previously
remaining in the alarm clock of the calling process.
Standards Conformance
alarm is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
The X/Open Portability Guide II of January 1987;
IEEE POSIX Std 1003.1-1988 with C Standard Language-
Dependent System Support;
and NIST FIPS 151-1.
(printed 6/20/89)